JP2522321B2 - Electrophotographic copier with automatic paper select function - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electrophotographic copying machine having an automatic paper select mode.

2. Description of the Related Art Some electrophotographic copying machines have an automatic paper selection mode.

In this type of electrophotographic copying machine, when the automatic paper select mode is selected, the size of the original is first detected. Alternatively, the size of the document is detected along with the operation of the automatic document feeder (ADF). Next, a paper feed port in which paper (copy paper) suitable for the detected document size is set is selected. After that, the normal copying operation is performed.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional electrophotographic copying machine with the automatic paper selection function, the copying operation does not start if there is no paper in the selected paper feed port. However, the concept of automatic copy is that when the start key is pressed, the copy is completed without any thought, so it is desirable that the operability of copy is further improved.

Originally, the fact that the paper is not in the paper feed port selected at that time is not a factor of copy prohibition. A person who wants to make a copy in the automatic paper select mode normally has a white copy paper (hereinafter referred to as a standard paper) which is a copy of the target document regardless of the state of the electrophotographic copying machine. Therefore, even if the electrophotographic copying machine selects a paper feed port without paper, I want the copying operation (or the operation of the system including ADF) to start regardless of that. is there. As a result, if the desired paper is not found in any of the paper feed ports, the paper may be set at that time.

Also, in the past, if there was paper in the selected paper feed port, the ADF was activated to detect the size of the original and the optimum paper was searched for, so all the set paper is nonstandard paper such as color paper. When is this
ADF operation was useless.

An object of the present invention is to provide an electrophotographic copying machine which has improved operability of copy work in the automatic paper select mode.

An electrophotographic copying machine having an automatic paper selection function according to the present invention is provided with a plurality of paper feed ports, paper feeding means for feeding paper, and an electrostatic latent image of a document exposed. Copying means by paper feeding means, document size detecting means for detecting the size of an original, paper type detecting means for detecting the type of paper at each paper feed port, and paper at each paper feed port Paper feed means for detecting the presence or absence of paper, a magnification input means for selecting a copy magnification, a document size detected by the document size detection means, and a copy magnification set by the magnification input means. The optimum paper is searched from among the papers and the mode that activates the automatic paper selection means that selects the paper feed port with the optimum paper If the operating means for selecting and the automatic paper selecting means cannot find the optimum paper, the releasing means for releasing the selection by the operating means, and the paper detecting means determines that the paper of the selected paper feed port is not present. Then, when the prohibiting means for prohibiting the copy operation by the paper supplying means and the copying means and the mode for operating the automatic paper selecting means are selected by the operating means, the state of the paper in all the paper feed ports is detected. If the standard paper does not exist in any of the paper feed openings, the prohibiting means is operated to prohibit the copy operation, and if there is even one paper, there is a paper feed opening. The start of the copying operation is permitted without activating the prohibition means, and is set by the magnification input means when the size of the original is detected by the original size detection means. Locate the paper feed port best paper is set and a copy magnification and the original size which is composed of a control means for selecting the feed port.

Function In automatic paper selection mode, even if there is no paper in the selected paper feed port, if standard paper exists in any of the paper feed ports, the start of the copying operation is permitted,
Find the paper source where the optimum paper is set and select the paper source. Even if there is paper in the selected paper feed port, if there is no standard paper in any of the paper feed ports, the copying operation is not started. As a result, the function of automatic paper selection is enhanced.

Embodiments Embodiments of the present invention will be described below in the following order with reference to the accompanying drawings.

Copy machine configuration b. Operation panel c. Copy machine controller configuration d. Copy machine operation <d-1> Main routine <d-2> Paper select <d-3> Paper empty display control <d-4> Copy operation <d-5> Automatic paper selection e. ADF operation Regarding the processing of the automatic paper selection mode particularly related to the present invention, especially <d-3> and <d-4 in section (d).
The first half of> and <d-5>.

(A) Construction of Copying Machine FIG. 2 shows a schematic sectional view of an electrophotographic copying machine according to the present invention.

The copying mechanism of the main body 1 of the electrophotographic copying machine is the same as that of the conventional electrophotographic copying machine. A photoconductor drum 2 that can be driven to rotate counterclockwise is arranged in the center of the copying machine body 1. Around the photoconductor drum 2, a main eraser lamp 3, a sub-charger 4, and a sub-eraser are provided. A lamp 5, a main charging charger 6, a developing device 7, a transfer charger 8, a transfer paper separating charger 9, a blade type cleaner device 10 and the like are sequentially arranged. The photoconductor drum 2 is a drum provided with a photoconductor (for example, selenium) on the surface thereof, is irradiated with light by the eraser lamps 3 and 5 for each copy, and is charged by passing through the charging chargers 4 and 6. Image exposure from the optical system described below is performed. The motor M1 drives the photosensitive drum 2 and the like.

The optical system is installed below the platen glass 11 so as to scan a document image. The optical system includes a light source 12 and a first mirror 1
3, second mirror 14, third mirror 15, projection lens 16, fourth
It is composed of a mirror 17. The original image reaches the photosensitive drum 2 via the mirrors 13, 14, 15, 17 as shown by the line 18. The fixed position switch SW50 is provided to detect whether or not the optical system is at a predetermined position during scanning. The magnification is set by moving the projection lens 16 with the motor M4 in the optical axis direction. The motor M3 drives the optical system. When the copy magnification is n, the light source 12 and the first mirror 13 correspond to the rotation of the photosensitive drum 2 at the peripheral velocity v (constant regardless of equal magnification or variable magnification) by the motor M3 (v / It moves to the left at a speed of (n), and at the same time, the second mirror 14 and the third mirror 15 move to the left at a speed of (v / 2n). As the image moves, the image is exposed from the fourth mirror 17 on the photosensitive drum 2 in a slit shape.

On the left side of the copier body 1, automatic paper feed cassettes 20,21
Are installed at the upper paper feed port and the lower paper feed port, respectively. The paper in the automatic paper feed cassettes 20 and 21 is selectively supplied into the copying machine main body 1 by respective paper feed rollers 22 and 23, passes through each pair of transport rollers 24 and 25, and is pressed by a timing roller It is transported to 26, where it temporarily waits.

At the time of transfer, the paper fed by the timing roller 26 comes into close contact with the photosensitive drum 2 at the transfer section, and the toner image is transferred by corona discharge of the transfer charger 8. Next, the corona discharge of the separation charger 9 and the transfer paper The photosensitive drum 2 is separated from the photosensitive drum 2 by its own waist strength. Subsequently, the paper is conveyed to the right as the belt 27 rotates in the clockwise direction while being sucked onto the conveyor belt 27 provided with an air suction means (not shown). Next, the toner image is fused and fixed by passing through the fixing device 28. Then, it passes through the discharge roller pair 29 and is discharged to the tray 30 outside the copying machine main body 1 or a collating machine (not shown).

The paper type switches 401, 402 and 403, 404 are micro switches for detecting the type of paper in the cassettes 20, 21, respectively. Paper size detection switch 410
Reference numerals 413 and 414 to 417 denote microswitches arranged in parallel with the upper and lower paper feed ports, respectively, and are set in the vertical or horizontal direction with respect to the paper size and paper feed direction in the cassettes 20 and 21. Is detected. The size that can be copied, that is, the size of the paper that can be cassette in each paper feed unit is, for example, [A3], [A4], [A5], [B4], and [B5].
Vertical and horizontal can be selected for 4] and [B5]. The switches 420 and 421 also detect the attachment / detachment of the cassettes 20 and 21, which means that the presence / absence of paper at the paper feed port is indirectly detected. Then, the size and setting direction of the paper is detected by a 4-bit code corresponding to the combination of ON / OFF of the switches 410 to 413 and 414 to 417,
It is stored in the built-in RAM of CPU1 of the control circuit (see FIG. 6). An example of the code table for the switches 410 to 413 is shown in the table below. This table shows that the switches are turned on as [0] and turned off as [1]. If all the switches are turned off, the cassette 20 is not attached to the paper feeding unit, that is, the paper is not loaded. Nothing will be detected.

Next, the detection of the type (color) of the paper set in the cassette 20 by the sensors 401 and 402 will be described with reference to FIG. As shown in FIG. 3A, a display plate 35 having a magnet M at one end is positioned on one side surface 20b of the cassette 20 in the direction of inserting the cassette into the cassette insertion opening 20a. On the other end side of the display plate 35, as shown in FIG. 3 (b), four colors of black B, white W, red R and yellow Y are displayed. This color display portion is inserted into the space formed by the side surface 20b and the guide plate 20c, and the display plate 35 is
Can be moved in the cassette insertion direction. On the display plate 35, the position of the magnet M changes for each color, and a color signal is obtained by a combination of ON / OFF of the sensors 401 and 402. The guide plate 20c is provided with a window 20d, and the color set by moving the display plate 35 can be visually identified through the window 20d.

Returning to FIG. 2, the automatic document feeder (AD
In the document transport unit (DF) 300 of F), the sensor
310 detects whether a document is fed or not, and a sensor 311
Detects whether there is a document on the document tray 304.

The motor 301 rotates the DF document transport belt 305,
The motor 302 feeds a document from a document tray 304.

When copying, if you press the start key on the operation panel shown in section (b), the automatic document feeding function first works, and the DF300
Sends out the original on the original tray 304, and moves the original to a fixed position on the original glass 11 on the upper surface of the copying machine main body 1 by the belt 312. During the feeding, the size of the document is determined by the sensor 310.

After the belt is stopped after moving, the copier body 1
Starts to work. This mode is set by connecting the ADF and placing a document on the document tray 304. The DF300 can be opened and closed like a document cover. When the document is manually placed on the document glass by opening and closing the DF300, the ADF mode is released and the normal copying operation is executed. When the ADF mode is released, the document size cannot be detected, so that if the automatic paper select mode is selected, this is also released.

(B) Operation Panel FIG. 4 shows the operation panel. The operation panel is provided with keys indicated by the following reference numbers.

50: Print button to start copying.

51: Number display LED for displaying the number of copies.

52: Paper empty display.

53: Exposure up key. 54: Exposure down key.

60-69: Numeric keypad for setting the number of copies and the like.

70: Interrupt key for making an interrupt copy.

71: The role of the stop key to stop multi-copy, and the dual-purpose key to clear the number.

75: Paper select key.

76-79: Select display of A3, B4, A4, B5 respectively.

80: A key to select the reduction ratio from A3 to A4.

81: Reduction key for selecting the reduction ratio from A3 to B4.

82: Enlargement magnification select key from A4 to A3.

83: Enlargement magnification select key from B4 to A3.

84: Same-size select key.

85-88: Select display of select keys 80-83, respectively.

89: Same size selection display.

Fig. 5 shows the ADF operation panel installed on the DF300. This operation panel is provided with a select key 320. The display LEDs 320a, 320b, and 320c indicate that the automatic paper select mode, the automatic magnification select mode, and the manual mode have been selected. Each time the select key 320 is pressed, the selected mode changes and the LED lights up.
Will change.

(C) Configuration of control section of copier FIG. 6 shows a CPU 1 (20
The input / output configuration of 1) is shown. Various signals shown in the figure (main motor, developing motor, timing roller clutch, upper paper feed clutch, lower paper feed clutch, charging, transfer), various sensors, keys, etc. (50, 52, 53, 60-71, 80-8
4,401-404,410-417,420,421) switch matrix 2
04 is connected. The output terminal has a 4-digit number display 51 and
The LED matrix (76-79, 85-88) is connected and driven by the CPU 1 via the decoder 207. Further, the paper empty display 52 and the same-magnification display 89 are also connected.
The bus 214 is a communication line for connecting to another CPU (CPU2, CPU3).

FIG. 7 shows the input / output configuration of the CPU2 (202) that controls the optical system. CPU2 I / O port is scan motor M3
A scan motor control circuit 205 for controlling the
It is connected to a zoom lens control circuit 206 that controls a motor M4 that moves the projection lens 16. In addition, the position roller SW50 of the optical system and the timing roller at the same magnification
A signal from the switch SW51 that generates a timing signal for rotating the 26 is input. This CPU2 communicates with the CPU1 via the bus 214 as described above.

FIG. 8 shows the input / output configuration of the CPU3 (203) that controls the DF300. The CPU 3 outputs signals to the conveyor belt motor 301 and the paper feed motor 302, and receives signals from the document feed sensor 310 and the document detection sensor 311. further,
The select key 320 and the displays 320a, 320b, 320c are connected.
The CPU 3 also communicates with the CPU 1 via the bus 214.

(D) Operation of Copying Machine Body The following outlines the contents of the program of the CPU 1 that controls the copying machine body 1.

<D-1> Main routine FIG. 9 shows a schematic flowchart of the CPU 1. When the CPU1 is reset and the program starts, first, the RAM is cleared, various registers are initialized, the CPU1 is initialized, and the device is initialized (step S1).

Next, the internal timer, which is built in the CPU 1 and is preset by the initial setting, starts the internal timer (step S2). Next, various processes, that is, automatic paper selection (step S3), paper empty display control (step S4), and copy operation (step S5) are sequentially performed. Next, data communication with the CPUs 2 and 3 is performed (step S
6).

When all the subroutine processes are completed, the process waits for the end of the first set internal timer (step S7).
The routine ends, and the process returns to step S2. Various timers appearing in the subroutine are counted using the length of time of this one routine. (Various timer values determine the end of the timer depending on how many times this one routine is repeated.) <D-2> Paper select Fig. 10 shows a paper select routine (step S3).
Shows the flow of.

If the paper select switch 75 is turned on (step S12) when copying is not in progress (step S11),
If the first paper feed is currently selected at the N edge (step S1
3) Then, the second paper feed is selected (step S14), and if the second paper feed is selected, the first paper feed is selected (step S15) and the paper size code is input. Then, the paper size code conversion routine (details will be described later) is called (step S16), and the set paper size LEDs 76-79 are turned on (step S17).

FIG. 11 shows a paper size code conversion routine.
The paper size is coded as shown in the table above. If the input paper size code is "4" (step S20), it is B5 length, so the paper length is 257.
mm, paper width 182 mm is stored (step S30).

Below, if the paper size code is "5" (step
S21), A4 portrait, "6" (step S22), B4 portrait, "7"
If (step S23), A3 portrait, if "10" (step
S24), B5 landscape, if "11" (step S25), it is determined to be A4 landscape and the respective paper length and paper width are stored (steps S30-35). If it is not the above code, it is determined that there is no paper (step S26).

<D-3> Paper Empty Display Control FIG. 12 shows the flow of the paper empty display control routine (step S4). In the automatic paper select mode (step S51), it is determined whether all the paper feed ports of the machine are paper empty (step S52), and if it is empty, the paper empty display 52 is turned on (step S54), If it is not empty, it is judged whether there is standard paper in any of the paper feed ports (step S53). If there is no standard paper, the paper empty display is lit (step S54), and if there is standard paper, the paper empty The display is turned off (step S56). If it is not in the automatic paper select mode, if the selected paper feed port is paper empty (step S5
5), turn on the paper empty display (step S5
4) If not empty, the light is turned off (step S56).

In this embodiment, in the automatic paper selection mode, the paper empty display is turned on when color paper is set in all the paper feed ports. Even if there is no standard paper, the paper empty display is not turned on and the size incompatibility flag described later is set to 1
Alternatively, the automatic paper select mode may be canceled.

<D-4> Copy Operation FIG. 1 shows the flow of the copy operation routine S5. When the paper empty display 52 is off at the ON edge of the print button 50 (step S60) (step S6)
1) If the ADF is not used (step S62), the copy start flag is set to "1" (step S63). If the ADF is used (step S62), if there is a document in the document tray 304 (step S62)
S64), the ADF start signal to DF300 is set to "1" (step S65). If the paper empty display 52 is on (step S61), the process proceeds as it is.

When the timing is not the ON edge of the print button 50 (step S60), if the ADF is used (step S7).
0), when the document original position signal from the DF300 becomes "1" (step S71), if the ADF mode is the automatic paper select mode (step S72), the automatic paper select routine (Fig. 13) is called (step S71). S73). As a result, if the size incompatibility flag is "0" (step S7
4) The copy start flag is set to "1" (step S75).
If the size incompatibility flag is "1", 32c is lit up and 32a, 3a
Turns off 2b and automatically switches the ADF mode to manual mode (step S76). By automatically setting the manual mode as in the present embodiment, a person who is uncomfortable looking for a paper can copy a copy even if it is not the optimum paper if he / she starts printing as it is. The person should set the optimum paper.

The following copying operation is the same as the conventional one. Step S81
When the copy start flag becomes "1" in, the main motor M1, the developing motor are turned on, the charging charger, the transfer charger, etc. are turned on, the copy start flag is set to "0", and TA (timer A), T- B (timer B) is set (step S82). If the upper paper feed cassette is selected (step S84), the upper paper feed roller clutch (not shown) is turned on (step S85). If the lower sheet feeding cassette is selected (step S86), the lower sheet feeding roller clutch (not shown) is turned on (step S87).

In step S91, the judge of TA is executed and T-
When it is time to end A, the upper and lower paper feed roller clutches are turned off (step S92).

In step S101, the judgment of TB is performed. T
At the timing when -B ends, the scan signal is turned on (step S102).

In step S111, when the timing signal becomes "1", the timing roller clutch (not shown) is turned on, and T
-C is set (step S112).

In step S121, the charging / scanning signal / timing roller clutch is turned off at the timing when TC ends (step S122).

In step S131, the return signal of the optical system is "1"
Is satisfied, that is, when the return is started, it is next determined whether the multi-copy copy has been completed (step S13).
2) If not, the copy start flag is set to "1" (step S133). Then, when the scanner that has left the fixed position comes back and the fixed position sensor SW50 is turned on (step S134), the developing motor and the transfer are stopped, and T
-D is set (step S135).

At the timing when TD ends (step S15
1) Stop the main motor M1 (step S152).
Then, the result of the processing so far is output (step S15).
Five).

<D-5> Automatic paper selection routine FIG. 13 shows the automatic paper selection routine S73. D
The document size data detected and transmitted by the CPU 3 which controls the F300 is temporarily stored in the A register (step
S160).

Next, the A register compares with the paper size of the upper paper feed cassette 20 (step S161). If they are the same and the paper types are standard paper, that is, the sensors 401 and 402 are both off (step S162), the size incompatibility flag is set to "0" (step S163), and the upper paper feed port is selected (step S164). Next, the A register compares with the paper size of the lower paper feed cassette 21 (step S165). If the paper types are the same and the standard paper is the same, that is, if the sensors 401 and 402 are both off (step S166), the size incompatibility flag is set to "0" (step S167), and the lower paper feed port is selected (step S168). If it is not equal to the paper size of either the first paper feed port or the second paper feed port, the size mismatch flag is set to "1" (step S169).

(E) Operation of ADF FIGS. 14 (A) and 14 (B) show a schematic flow of the CPU 3 controlling the DF300. When the CPU3 is reset and the program starts, the RAM is cleared, C is set for various registers, etc.
Initialize PU3 and initialize the device to the initial mode (step S651).

Next, an internal timer which is built in the CPU 3 and whose value is set in advance by default is started (step S652).

Next, the subroutines of document size detection (step S654) of document control (step S653) and mode selection (step S655) are sequentially called. When all the subroutine processes are completed, one routine is terminated after the first set internal timer is completed (step S656). Using the length of time of this one routine,
Counts various timers that appear in the subroutine. (Various timer values determine the end of the timer depending on how many times this one routine is counted.) Further, as shown in FIG. 14B, data communication with the CPU 1 (step S658) Interrupt request from CPU1 (step
S657) is performed by the interrupt routine regardless of the main routine.

FIG. 15 shows the document control S653. When there is a document in the document tray (document detection sensor 311 is on) (step S661), when the ADF start signal from CPU1 becomes "1" (step S662), or when the document feed flag becomes "1". (Step S663), after setting the original feeding flag to "0" (step S664), the conveyor belt motor 301 is turned on, and the original feeding motor 302 is turned on (step S66).
Five).

Next, processing is performed in a document feed processing routine (step
(S666), when the set number of scans are completed (step S667), the scan end flag is set to "1" (step S668).

When the scan end flag is "1" (step S669), the scan end flag is set to "0" (step S670), and the document discharge processing routine is performed (step S671).

FIG. 16 shows the flow of the document feeding process routine S666.
When the document is fed and the document feeding sensor 310 is turned on (step S681), the flag K is set to "1" and the timer Y1 is started (step S682). This timer A1
Used to stop the document feeding motor 302 to prevent the previous document from being fed and the next document to be fed, and the timer value until the document reaches the position where the conveyor belt 305 is driven. Is set.

Next, when the flag K is "1" (step S683), when the OFF edge of the document feed sensor 310 comes, that is, when the trailing edge of the document is detected (step S684), the flag K is set to "0" and the timer is set. Start A2 (step S685). Timer A2
The value of is set to a value until the trailing edge of the original reaches the original leading edge fixed position on the original glass.

When the timer A1 ends (step S691), the document feed motor 302 is stopped (step S692). When the timer A2 ends (step S693), the conveyance belt motor 301 is stopped (step S694), and a document home position signal is sent to the CPU 1 (step S695).

FIG. 17 shows the flow of the document discharge processing routine S671.
When the document detection sensor 311 determines that there is still another document in the document tray (step S701), the document feed flag is set to "1" (step S702). If not, the conveyor belt motor 305 is normally rotated (step S703), and the timer B is started (step S704). Timer B
Is set for the time (maximum length) of the original on the original glass can be ejected. At the end of timer B (step
(S705), the conveyor belt motor 301 is turned off (step S)
706).

FIG. 18 shows the flow of the document size detection routine S654. At the ON edge of the document detection sensor 311 (step S71
1) Start timer DU (step S712).
Next, when the OFF edge of the document detection sensor 311, that is, the rear end of the document passes (step S 713), the timer DU is stopped (step S 714), and the value obtained by multiplying the value at that time by the document conveyance speed, ie, the length of the document Is stored in the A register (step S715). If the value of the A register is 182 (mm) or less (step S716), it is determined that the document size is B5 landscape (step S717), and if it is 210 (mm) or less (step S718), A4 landscape. Is determined (step S719).
If it is 257 (mm) or less (step S720), it is determined to be B5 portrait (step S721), and if it is 297 (mm) or less (step S722), it is determined to be A4 portrait (step S72).
3), if it is 364 (mm) or less (step S724), it is determined to be B4 (step S725), and if it exceeds 364 (mm), A
It is determined to be 3 (step S726).

In order to make an accurate judgment, another sensor for detecting the width of the original is provided next to the sensor 310, and by using this ON / OFF, the same length but different width (eg A4 width, A5 length, etc.) You only have to identify things.

FIG. 19 shows the flow of the mode select routine (step S655). When the mode select switch 320 is turned on, the LED 320a is turned on at the ON edge (step S731), that is, if the automatic paper select mode is selected (step S732), the automatic magnification select mode is set (steps S733, S734) and the LED 320b is set. Lights up, that is, when the automatic magnification selection mode is selected (step S735),
In manual mode (steps S736, S737), in other cases, in automatic paper select mode (step S7
38, S739). Switch each.

Effect of the Invention In the automatic paper selection mode, if standard paper exists in any of the paper feed ports even if there is no paper in the selected paper feed port, the copy operation starts (the ADF starts the document feed operation). , And), search for the paper feed port where the optimum paper is set, and select the paper feed port. Even if there is paper in the selected paper feed port, the copying operation is not started if there is no standard paper in any of the paper feed ports. As a result, the function of automatic paper selection is enhanced and the operability of copy work is improved.

[Brief description of drawings]

FIG. 1 is a flowchart of a copy operation subroutine according to the present invention. FIG. 2 is a schematic sectional explanatory view of an electrophotographic copying machine according to an embodiment of the present invention. FIGS. 3A and 3B are perspective views showing a mechanism for setting the color of paper. FIG. 4 is a plan view of the operation panel of the copying machine. FIG. 5 is a plan view of the ADF operation panel. Fig. 6 shows the microprocessor CP that controls the main body of the copying machine.
FIG. 3 is a circuit diagram showing input / output to U1. FIG. 7 is a circuit diagram showing input / output to / from the microprocessor CPU2 which controls the optical system. FIG. 8 is a circuit diagram showing input / output to / from the microprocessor CPU3 which controls the ADF. FIG. 9 is a flowchart of the main routine of the program for controlling the main body of the copying machine. FIG. 10 is a flowchart of the paper select subroutine. FIG. 11 is a flowchart of a paper size code conversion subroutine. FIG. 12 is a flowchart of a paper empty display control subroutine. FIG. 13 is a flowchart of a subroutine for automatic paper selection. FIGS. 14A and 14B are flowcharts of the main routine of the program of the microprocessor CPU3 that controls the automatic document feeder (ADF). FIG. 15 is a flowchart of a document control subroutine. FIG. 16 is a flowchart of a subroutine for document feeding processing. FIG. 17 is a flow chart of a subroutine of document discharge processing. FIG. 18 is a flowchart of a document size detection subroutine. FIG. 19 is a flowchart of the mode select subroutine. 1 ... Copier body, 2 ... photosensitive drum, 11 ... original glass, 12 ... exposure lens, 16 ... magnifying lens, 20 ... upper sheet feeding cassette, 21 ... lower sheet feeding cassette, 52 ...... Paper empty display, 201 ...... CPU that controls the copier body, 300 ...... Document transport unit, 310 …… Document size detection switch, 320 …… Mode select key, 320a …… Automatic paper select display LED, 401 ~ 404: Paper type detection sensor, 410 to 417: Paper size detection sensor, 420,421: Paper empty detection sensor.

Claims (1)

(57) [Claims] 1. An electrophotographic method which comprises a plurality of paper feed ports and which feeds paper, and which forms an electrostatic latent image of an original on a photoconductor and transfers it to the paper fed by the paper feeding means. Copying means, original size detecting means for detecting the size of the original, paper type detecting means for detecting the type of paper at each paper feed port, and paper detecting means for detecting the presence or absence of paper at each paper feed port , The optimum paper is selected from the papers in each paper feed port based on the magnification input means for selecting the copy magnification, the document size detected by the document size detection means, and the copy magnification set by the magnification input means. The automatic paper selection means for searching and selecting the paper feed port with the optimum paper, the operation means for selecting the mode for operating the automatic paper selection means, and the automatic paper selection means. When the per-select means cannot find the optimum paper, the cancel means for canceling the selection by the operating means and the paper detecting means determines that the paper in the selected paper feed port is not present. When the prohibiting means for prohibiting the copying operation by the copying means and the mode for operating the automatic paper selecting means are selected by the operating means, the state of the paper at all the paper feed ports is determined by the paper detecting means and the paper type detecting means. If no standard paper is found in any of the paper feed ports, the prohibiting means is activated to prohibit the copy operation, and if there is a paper feed mouth in which even one standard paper exists, the prohibiting means is not activated. When the start of the copying operation is permitted and the size of the document is detected by the document size detection means, the copy magnification and the document support set by the magnification input means are set. Locate the paper feed port best paper is set and a's, an electrophotographic copying machine having an automatic paper selection function comprising a control means for selecting the feed port.